#if !defined( STRING_HASH_H)
#define  STRING_HASH_H
#include <string>

struct hash_string
{
std::size_t operator()(const std::string& s) const
{
	std::size_t hash_val = 0;
	std::string::const_iterator i, end;
	for (i = s.begin(), end = s.end() ; i != s.end(); ++i)
	  hash_val = 5 * hash_val + *i;
	return hash_val;
}
};

#endif	//STRING_HASH_H

